Carrying out Performance and Feasibility Study of Evaporator # D Stream towards performance optimization in TNPL Unit-I

Study of existing operations of the Evaporator#D stream towards performance optimization in achieving ❖ Water evaporation - 350 TPH ❖ HBL product concentration - 70 % ❖ Steam economy - 6.45

Feasibility study, detailed engineering - including equipment design and specifications, budgetary cost estimation, implementation schedule, and cost-benefit analysis with Return on Investment {ROI} (i) To achieve required water evaporation in Evaporator#D stream alone without Evaporator#C stream for firing 1300 MT of black liquor dry solids in Recovery Boiler#3 (HBL firing ~56 m3/hr, 70% solids). (ii)To achieve required water evaporation in Evaporator#D stream alone without Evaporator#C stream for firing 1300 MT of black liquor dry solids in Recovery Boiler#3 at 75% solids concentration HBL.

Feasibility study, detailed engineering - including equipment design and specifications, budgetary cost estimation, implementation schedule, and cost-benefit analysis with Return on Investment {ROI) - for Effect#5 online isolation for tube cleaning in the existing plant- Also evaluate the impact of online isolation in the existing evaporator operation.

Modification of existing HBL storage vessel or design of new pressurised storage vessel. Modification of one of the existing HBL storage vessel or Design a new pressurised storage vessel for the Evaporator #D Stream product - Heavy Black Liquor (HBL) - at a solids concentration of 70-75%. The vessel volume shall be determined based on an HBL firing requirement of 56-60 m3/hr. The new vessel shall be such that the temperature of the firing liquor in the storage vessel shall be ≥ 130 °C and the Indirect heaters for the firing black liquor in RB3 are not required. Compatibility of circulation pumps and firing pumps shall also be evaluated for the new requirement .